Systems capable of displaying a plurality of windows (in which messages and data during work are displayed) on a display of a PC (Personal Computer), etc. as a type of user interface GUI (Graphic User Interface) environment for graphically displaying buttons and menus are well known. Such systems can improve the operability of PCs by the visual effect achieved by the display of a plurality of windows.
One of such systems has been described in Japanese Patent Provisional Publication No. 2000-112613. The system of the Publication is capable of displaying a window while partitioning it into a plurality of areas called “panes”, displaying a plurality of independent windows, etc. for use of a piece of application software.